Cyclic Loading Test for Exterior Beam–Column Joints of CEFT Columns

Abstract

A cyclic loading test was performed to investigate the seismic performance of exterior beam-column joints of concrete-encased-and-filled steel tubular (CEFT) columns. Two specimens with steel beams and two specimens with precast concrete (PC) beams were tested under cyclic loading. The dimensions of the column cross section were 670×670 mm, which was a two-thirds-scale model of the prototype column. The test parameters for the steel beam and the PC beam were the beam depth (488 and 588 mm) and the flexural rebar ratio (1.1% and 1.5%), respectively. In the steel beam-CEFT column joints, continuity plates were used, while in the PC beam-CEFT column joints, couplers were used for the rebar connection. The steel beam-column connections failed due to early fracture of the continuity plate, and the PC beam-column connections failed due to rebar buckling and concrete spalling after beam yielding. The strength of the steel beam-column connections was evaluated using an existing design method, and the seismic performance of the PC beam-column connections was evaluated. On the basis of the test results, design considerations for beam-CEFT column joints were recommended.